In densely populated urban environments, fuel retail outlets represent sources of Volatile Organic Compounds (VOCs), particularly benzene, toluene, and xylene. These emissions occur during various operations including storage tank filling, underground storage, and vehicle refuelling at retail outlets. The contribution of VOC by fuel distribution infrastructure to urban VOC pollution has been adequately addressed by oil marketing companies (OMCs) by the installation of vapor recovery system which is deployed for the comprehensive capture of fugitive emissions.
This study employed a novel approach at an OMC Retail Outlet in Delhi, to evaluate benzene concentrations with different operational case studies. The methodology integrated continuous ambient air monitoring system equipped with VOC analyser of GC-PID technology alongside targeted forecourt measurements with handheld PID instrument. Benzene emissions during peak and off-peak hours, vehicle throughput, fuel sales volume, and operational activities are studied.
The results demonstrated that with VRS implementation, average concentrations remained below OSHA's permissible exposure limit (1000 ppb), though maximum values periodically spiked during high-traffic periods and underground tank filling operations. Temperature variations (8-21°C), traffic density, vehicle idling time, and operational practices were identified as critical determinants of benzene concentrations. With VRS system, benzene limits are within the 15-minute Short-Term Exposure Limit (STEL) values, ambient levels occasionally exceeded National Ambient Air Quality Standards (1.567 ppb) during cooler conditions with reduced atmospheric dispersion.
This case study addresses a critical finding by quantifying VOC emissions in real-world retail outlet operating conditions, establishing that properly implemented vapor recovery technology significantly reduces occupational exposure to further minimize both worker exposure and environmental emissions from fuel retail infrastructure.
Keywords: Benzene exposure, Vapor Recovery Systems, Fuel retail outlets, Occupational health, VOC emissions, Air quality